I have my 4 subs connected to a single amp just as Duke described. It's all fairly basic but I would suggest having a plan for running the wiring.
In my case, my living room is directly above a crawl space and I drilled 1/2" holes through my living room carpet and sub floor for access. I have a hole in back of my rack that holds the Dayton sub amp and a hole underneath each of the 4 subs. Remember, the spkr terminals are on the bottom of each sub and there's the option of using spiked or flat footers. I ran thickly coated 16 gauge wire suitable for outdoor use which wouldn't be needed indoors.
There are a lot of methods you or a ht installer could use to run the 4 sets of wiring inconspicuously. I'd definitely recommend hiding the wiring, however, since the finished look is so clean and even stylish. All that's visible just looks like a wooden pedestal.
In my 23x16 ft room, each of the 2 subs positioned along my front 16 ft. wall are actually hidden from view by each of my 6x2 ft. panel speakers. The 2 other subs, one along each of the 23 ft. side walls are visible but look good to my wife and I.
Oh yeah, and the whole system sounds awesome.
Tim